Whats even more interesting as an X marks the spot is the andes mountains right here on earth. All kinds of things leading to it being an extraterestrial airport. When it was built we had nothing that left the ground what so ever. But it seems like possibly slaves built a perfect runway and weird markers that can actually be seen from space. Check it out sometime, i think it was discovery or BBC that did an actual study on it, pretty awesome stuff.
You are totally assuming that we are of a similar technology but there are bound to be no similarities at all.
Any species able to come here into our solar system from another would have some kind of technology which allows them interstellar travel. This means that they have cracked the power problem and do not need any of the surface facilities we do. We need to think outside the box to even start to comprehend what tehcnology they have.
Art may come into it, its true, but technology naaah. Not a chance. They will be far far far in advance of us.
An interesting thought MA, my question would be 'Would an off world civilisation be as warlike and hostile as we appear to be and be concentrating on survival of a race with military ability intact.....or would they be concentrating on preserving their art, culture and the best of what their race had to offer?'
If the second option, and knowing perhaps that they as a race would not survive then I would imagine a satellite repository of the best of their culture, safely orbiting their world would suffice, or maybe a monolithic structure visible from space that any alien species would see clearly as they approached from space...sort of an 'x' marks the spot.
If my assumption may be true, then we have a number of possible sites to start exploring such
- on Mars I suggest the 'giant head' not to be mistaken with the 'Face of Mars' - the 'Face of Mars' - Phobos - Steins Asteroid - Iapetus - Tycho Crater
When researching locations of-earth we can compare some of our home-world facilities in relation to what we observe in other imagery for comparison (however obscured) to find out find we can identify as underground activities conducted in absolute secrecy. Compare Russian underground base complex Yamantau. Otherwise known as the place where the computers would take over the launching of all nuclear capabilities after catastrophy without assistance of human intervention...
Otherwise known as the Systema Perimeter or the dead-hand or more understandably - the hand of death - involving cold war systems that would in effect destoy everyone on earth following the mutually assured destruction policy. It's unfortunately still operational to this day. In the US the is an underground "continuity of government program yet much of the world does not want to dwell on such plans as reality.
Just thought I'd share a glimpse of what's been on my my when checking out possible structure off-world too wonder what became of them - if there was such a thing.
Let's take a look at how an Earth-based nation would construct an underground survival facility and the surroundings in order to compare with related places on other celestial objects.
